Materials for Wood Construction, Lumber, and Below-Grade Foundation Systems

Comprehensive practice flashcards covering materials for wood construction (engineered wood products, glulam, structural composite lumber, I-joists, trusses, panels, fasteners, and connectors), lumber characteristics (microstructure, hardwoods, softwoods, sawing, seasoning, dimensions, and preservation), and below-grade foundation systems (substructures, light frame integration, crawl spaces, slabs-on-grade, basements, concrete block walls, precast foundation systems, and reinforcement).

Engineered Wood Products

Manufactured wood products specifically engineered for structural applications, including glue-laminated wood (glulam), structural composite lumber, wood I-joists, plywood, oriented strandboard (OSB), and wood trusses.

Industrial Wood Products

Nonstructural manufactured wood products such as particleboard and medium-density fiberboard (MDF) commonly used in cabinet work, furniture, and shipping containers.

Particleboard

An industrial engineered wood product made from small wood particles such as sawdust, sawmill shavings, and tiny chips bonded together with synthetic resin adhesive under heat and pressure.

Medium-Density Fiberboard (MDF)

A waste-wood product made by breaking down wood composites into fine wood fibers, which are glued and pressed together to form dense boards with smooth surfaces suitable for precise machining and painting.

Limitations of Large Solid Sawn Lumber

Solid sawn lumber spanning long distances requires large girth trees that are protected from harvesting, uneconomical, and difficult to dry to an acceptable moisture content without severe defects.

Glue-Laminated Wood (Glulam)

An engineered structural wood product manufactured by gluing together individual laminations of solid sawn lumber with their grains running parallel along the longitudinal axis.

Glulam Beam Anatomy

A structural member typically manufactured by face-gluing individual $1\frac{1}{2}\text{ in.}$ thick laminations of solid sawn lumber, which are end-joined using finger joints.

Lamination

The industrial process of making a structural material thicker and sturdier by bonding together multiple layers of materials such as wood lumber or veneers.

Lamination Effect

The structural principle wherein natural defects (such as knots) dispersed across individual glulam laminations do not align, resulting in higher strength and stiffness values than an equivalent solid sawn timber.

Large Cross-Section Glulam Construction

Extra-large glulam members created by bonding individual lumber laminations together both side-by-side (edge-to-edge) and face-to-face.

Glulam Long-Span Application

Glulam beam configurations capable of achieving massive dimensions, such as a $12\text{ in.}$ wide by $7\text{ ft}$ deep member spanning $82\text{ ft}$.

Glulam Column

A vertically oriented glue-laminated compression member engineered to support significant vertical axial loads and lateral bending forces.

Glulam Truss

A heavy-timber structural framework formed by interconnecting glulam chords and web members into rigid triangular configurations.

Sheshan Golf Course Bridge

A large-scale curved glue-laminated timber arch bridge constructed near Shanghai, China.

Tension Force

A structural force that acts to pull a member apart, attempting to elongate the body along its line of action.

Compression Force

A structural force that acts to squeeze a material together, attempting to shorten the body along its line of action.

Tension and Compression Forces

The two primary opposing internal stresses that develop across the cross section of a bending member, separated by a central neutral layer where bending stresses equal zero.

Neutral Layer (Neutral Axis)

The horizontal longitudinal plane along a beam where the fibers experience neither compressive nor tensile stresses during bending.

Balanced Glulam Beam

A glulam beam whose layup is symmetrical in lumber quality and strength ratings above and below the beam's mid-depth, suitable for members undergoing stress reversals.

Unbalanced Glulam Beam

A glulam beam where higher-grade lumber is placed on the tension side (bottom) than on the compression side (top), optimizing material economy for simple-span gravity loading.

Glulam Layup (Balanced vs. Unbalanced)

The arrangement of wood laminations where unbalanced layups concentrate high-grade tension laminations at the bottom, whereas balanced layups place high-grade laminations at both top and bottom edges.

TOP Stamp on Unbalanced Glulam

A mandatory manufacturer's stamp placed on the compression face of an unbalanced glulam member to ensure it is installed right-side up.

Single-Span Glulam Beam

A simple-span beam loaded downward that develops compression throughout the top half and tension throughout the bottom half, making the use of an unbalanced beam preferred for economy.

Overhanging (Cantilevered) Glulam Beam

A beam configuration with an overhang where bending stresses reverse over the support, requiring the use of a balanced glulam beam.

Continuous Glulam Beam

A multi-span beam resting on three or more supports that experiences stress reversal along its length, necessitating a balanced glulam member.

Framing Appearance Grade Glulam

The lowest appearance grade of glulam where knots, splits, glue smears, and squeeze-out are permitted because the member is concealed from view.

Industrial Appearance Grade Glulam

A glulam appearance grade specified where visual appearance is relatively unimportant, such as in warehouse spaces or when the timber will be enclosed by finish materials.

Glulam Headers

Industrial appearance grade glulam beams manufactured specifically to match standard wood-frame wall widths of $3\frac{1}{2}\text{ in.}$, $5\frac{1}{2}\text{ in.}$, and $7\frac{1}{4}\text{ in.}$

Architectural Appearance Grade Glulam

A high-quality glulam appearance grade intermediate between industrial and premium grades, intended for exposed structural elements.

Premium Appearance Grade Glulam

The highest glulam appearance grade, specified in high-visibility architectural applications where exposed timber aesthetics are critical.

Glulam Grade Stamp

A standardized trademark stamp certifying conformance with ANSI/AITC A190.1, specifying agency, structural use (B, CB, C, T), appearance grade, allowable bending strength, modulus of elasticity, and species.

Structural Composite Lumber (SCL)

A family of engineered wood products manufactured by gluing together dried wood veneers or strands, encompassing Laminated Veneer Lumber (LVL) and Parallel Strand Lumber (PSL).

Laminated Veneer Lumber (LVL)

An engineered composite lumber product manufactured by gluing together dried wide wood veneers approximately $\frac{1}{8}\text{ in.}$ thick with the grain of all veneers running parallel in the longitudinal direction.

LVL Grain Orientation vs. Plywood

The grain in all veneers of an LVL member runs parallel to the span length to maximize bending strength, whereas plywood alternates adjacent veneer grain at right angles.

LVL Standard Dimensions

Structural members commonly produced in thicknesses of $1\frac{3}{4}\text{ in.}$ and depths extending up to $18\text{ in.}$

Parallel Strand Lumber (PSL)

A high-strength structural composite lumber product made by coating narrow, elongated wood veneer strands with waterproof adhesive and consolidating them under heat and pressure.

Laminated Strand Lumber (LSL)

An engineered structural composite lumber product manufactured from short, flaked wood strands bonded together with resin under pressure.

Cross-Laminated Timber (CLT)

A heavy-timber engineered wood panel composed of layers of solid sawn lumber glued together with each layer oriented perpendicular to adjacent layers for two-way structural strength.

Wood I-Joist

An engineered structural member featuring an I-shaped cross section composed of top and bottom wood flanges glued to a central web panel of plywood or OSB.

I-Joist Flanges

The horizontal upper and lower members of an I-joist made of solid sawn lumber or jointless Laminated Veneer Lumber (LVL), which resist bending tension and compression.

I-Joist Web

The vertical shear-resistant central panel of a wood I-joist, typically manufactured from $\frac{3}{8}\text{ in.}$ or $\frac{1}{2}\text{ in.}$ thick oriented strandboard (OSB) or plywood.

Wood I-Joist Web Joints

End-to-end connections between adjacent OSB or plywood web segments in a wood I-joist, constructed using either a butt joint or an angled scarf joint.

Wood I-Joist Dimensions

Standard sizes including depths of $9\frac{1}{2}\text{ in.}$, $11\frac{7}{8}\text{ in.}$, $14\text{ in.}$, and $16\text{ in.}$ with typical flange widths of $1\frac{3}{4}\text{ in.}$, $2\frac{1}{8}\text{ in.}$, $2\frac{5}{8}\text{ in.}$, and $3\frac{1}{2}\text{ in.}$

I-Joist Web-Flange Connection

A precision-routed grooved joint where the web panel is bonded into the center of the solid or LVL flange using high-strength structural adhesive.

Web Instability in I-Joists

The structural limitation that a thin OSB or plywood web has low lateral buckling resistance and requires web stiffeners or trusses for heavy point loads.

Wood Truss

A structural assembly consisting of individual solid lumber members interconnected in an array of rigid triangles to bridge long spans.

Rigid Triangle Principle

The geometric principle that a triangle cannot be distorted without altering the length of its sides, making trusses naturally stiffer than solid beams of equal weight.

Wood Truss Anatomy

The arrangement of top chords, bottom chords, and intermediate web members that meet at joints called panel points.

Panel Point

Any intersection point where the chords and web members of a truss connect to transfer axial forces.

Truss Nail Plate

A toothed connector plate made by punching teeth out of a galvanized sheet steel plate, pressed hydraulically into both sides of lumber at truss panel points.

Wood Truss Configurations

Standard truss profiles used in construction including common, dual-pitch, scissors, mono-slope, hip, and parallel chord trusses.

Common Truss

A symmetrical pitched triangular roof truss having equal top-chord slopes rising to a central peak.

Scissors Truss

A pitched roof truss with sloped bottom chords that create a vaulted or cathedral ceiling interior.

Mono-Slope Roof Truss

A single-slope triangular truss used for shed roofs or paired end-to-end and field-spliced on-site when a common truss is too large to transport.

Standard Roof Truss Spacing

The standard center-to-center installation spacing for light residential and light commercial wood roof trusses, which is $24\text{ in.}$ on center.

Floor Truss (Parallel Chord Truss)

A flat truss with parallel top and bottom horizontal chords made from $2\times 4$ lumber connected by web members, providing open webs for utilities.

Trussed Lintel

A prefabricated trussed header used over large door and window wall openings to support header loads without heavy solid timber.

Floor Truss Mechanical Opening

A built-in rectangular opening designed into the open web of a floor truss to allow large HVAC ductwork and pipes to pass through without cutting.

Wood-Steel Trussed Joist

A hybrid structural joist made with solid lumber top and bottom chords interconnected by diagonal tubular steel pipe web members.

Wood Panels

Large, flat sheets of engineered or industrial wood manufactured for structural sheathing (floors, roofs, walls) and nonstructural uses (siding, interior paneling).

Veneered Panels

Wood panels manufactured by gluing together thin sheets of peeled wood veneer under heat and pressure, classified as plywood.

Nonveneered Panels

Wood panels manufactured from wood strands, flakes, chips, or particles rather than continuous veneer sheets, including OSB and particleboard.

Manufactured Boards

Engineered board products including oriented strand board (OSB), particleboard, medium-density fiberboard (MDF), and plywood, each with distinct structural and machining properties.

Oriented Strandboard (OSB)

A nonveneered structural panel made by compressing and gluing cross-oriented rectangular wood strands under heat and waterproof resin adhesive.

OSB Strand Layering

An arrangement where surface strands are oriented along the panel's long axis and core strands are oriented perpendicular to it, mimicking plywood cross-graining.

OSB Racking Resistance

The ability of OSB panels to provide superior shear wall performance and racking resistance at a lower purchase cost compared to plywood.

OSB Limitations

A panel that cannot be sanded smooth, stained, or pressure-treated with preservatives, and is prone to edge swelling when exposed to standing water.

Whole-Envelope OSB Sheathing

The common construction practice of sheathing the complete structural envelope—floors, exterior walls, and roof—with OSB panels.

Plywood Panel

A structural panel composed of three or more thin layers of peeled wood veneers glued together with adjacent plies having their grain at right angles.

Plywood Nominal Size

The standard commercial dimension of plywood panels specified as $4\text{ ft} \times 8\text{ ft}$, with thicknesses ranging from $\frac{1}{4}\text{ in.}$ to $1\text{ in.}$

Plywood Actual Size

The undersized dimensions of a nominal $4\text{ ft} \times 8\text{ ft}$ panel, manufactured to $47\frac{7}{8}\text{ in.} \times 95\frac{7}{8}\text{ in.}$ to allow a $\frac{1}{8}\text{ in.}$ moisture expansion gap.

Rotary Slicing

The standard industrial process of peeling a continuous sheet of wood veneer from a rotating, debarked log using a long stationary knife blade.

Plywood Cross-Graining

The alternating perpendicular grain orientation of stacked veneer layers that equalizes panel strength and minimizes cross-panel shrinkage and swelling.

Face Veneers

The outermost top and bottom veneer plies of a plywood panel, whose longitudinal grain direction establishes the stronger structural axis of the panel.

Five-Layer, Six-Veneer Plywood

An even-veneer panel configuration where the two innermost plies run in the same direction, allowing both exterior face veneers to remain parallel.

Plywood Installation Orientation

The mandatory structural practice of installing panels with their long dimension perpendicular to the supporting joists or rafters.

Panel Expansion Gap

A mandatory $\frac{1}{8}\text{ in.}$ perimeter gap left between adjacent wall, floor, or roof sheathing panels to prevent buckling from moisture expansion.

Metal Edge Clips (H-Clips)

Small metal clips placed between unsupported edges of adjacent roof sheathing panels to maintain panel continuity and provide an expansion gap.

Interlocking Joinery

Traditional mechanical woodworking joints designed to fit members together, including mortise-and-tenon, housed mortise-and-tenon, and dovetail joints.

Finger Joint

A high-strength glued joint formed by cutting complementary interlocking finger-shaped profiles into the ends of two lumber pieces and pressing them together with adhesive.

Nail Anatomy

The three essential components of a nail: the impact head, the elongated cylindrical shank, and the sharp diamond-shaped driving tip.

Nail Steel Composition

Low- or medium-carbon steel wire that is cold-formed and heat-treated to maximize structural driving stiffness and shear resistance.

Types of Nails

Standard fasteners including common, box, sinker, duplex, casing, finish, ring-shank, fluted-shank, and roofing nails, differentiated by head and shank geometry.

Common Nail

The most widely used structural nail in wood-frame construction, featuring a flat head and a thick shank that provides maximum shear strength.

Box Nail

A thin-shanked nail with a flat head used for attaching wood siding and shingles without splitting the wood.

Sinker Nail

A thin-shanked nail featuring a countersunk tapered head and a vinyl coating that lubricates driving and increases long-term withdrawal resistance.

Duplex Nail

A double-headed nail designed for temporary construction applications such as concrete formwork and scaffolding, allowing easy claw-hammer removal.

Casing Nail

A finishing fastener with a small cone-shaped head designed to be countersunk beneath the surface of wood trim, window casings, and decks.

Finish Nail

A slender nail with a very small cupped head designed to be driven flush or countersunk for fine cabinetry and interior finish carpentry.

Ring-Shank Nail

A fastener featuring raised circular ridges along its shank that lock mechanically into wood fibers to provide superior withdrawal resistance in floor sheathing and drywall.

Fluted-Shank Nail

A high-carbon, heat-treated masonry nail with longitudinal flutes designed to penetrate and fasten wood directly into concrete or mortar joints.

Roofing Nail

A short, galvanized nail featuring an oversized flat head designed to secure asphalt shingles without tearing through the material.

Nail Penny Designation

The traditional American sizing system abbreviated as 'd' (from the Roman denarius), designating nail lengths from $2d$ ($1\text{ in.}$) up to $60d$.

Penny Size Formula (Up to 10d)

The mathematical formula for nail length: $\text{Nail length (inches)} = \frac{\text{Penny designation} + 2}{4}$

Common Framing Nail Sizes

The four most common nail sizes used in light wood frame construction: $6d$ ($2\text{ in.}$), $8d$ ($2\frac{1}{2}\text{ in.}$), $10d$ ($3\text{ in.}$), and $16d$ ($3\frac{1}{2}\text{ in.}$).

Nailed Connection Methods

The three primary techniques for driving nails into wood framing members: face nailing, end nailing, and toe nailing.

Face Nailing

Driving a nail perpendicular through the face of one member directly into the wide face of an adjacent member to achieve maximum connection strength.

End Nailing

Driving a nail through a member parallel into the end grain of an abutting member, providing the weakest withdrawal resistance.

Toe Nailing

Driving nails at approximately a $30^\boxplus$ to $45^\boxplus$ angle through the side of one member into the face of another, used where face nailing is inaccessible.

Pneumatic Nailing Gun

A power tool driven by compressed air that feeds and drives collated framing nails or staples rapidly into wood framing.